一、语法
参考原文:https://blog.csdn.net/xushaozhang/article/details/55053037
1.查询插入
(1)SELECT INTO
语句格式: Oracle:Create Table2 as Select column1,column2……From Table1 或 Create Table2 as Select * From Table1 MS SqlServer:Select column1,column2…… into Table2 From Table1 或 Select * into Table2 From Table1
Table2不存在的时候进行表数据复制,编译器会根据Table1的表结构自动创建Table2,Table2和Table1的结构基本上是一致的,但是如果已经存在Table2,则编译器会报错.
(2)INSERT INTO SELECT
语句格式:Insert Into Table2(column1,column2……) Select value1,value2,value3,value4 From Table1 或 Insert Into Table2 Select * From Table1
表复制必须要求Table2是事先创建好的;注意Table2的主键约束,如果Table2有主键而且不为空,则column1, column2...中必须包括主键;另外,注意语法,不要加values;
2.查询更新
原文:https://blog.csdn.net/xcbsdu/article/details/6736503
MS SQL Server的语法为: UPDATE A SET A1 = B1, A2 = B2, A3 = B3 FROM A LEFT JOIN B ON A.ID = B.ID Oralce和DB2支持的语法: UPDATE A SET (A1, A2, A3) = (SELECT B1, B2, B3 FROM B WHERE A.ID = B.ID)
二、函数
1.字符串转化为整型
CONVERT(INT,'字符串')
2.结果集 输出为一段字符串
SELECT STUFF((SELECT ','+A FROM tableFOR XML PATH('')),1,1,'')